The major objectives in the proposed research concern initial attempts to understand the basic powers of memory. The project will focus on a frequency-discrimination power of memory as basic to performance in frequency judgment tasks and specific recognition memory paradigms. Specific experiments will be directed at: (a) the empirical basis for frequency discrimination as a power of memory separable from "strength," (b) an evaluation of methodological developments designed to assess subjective frequency values of events, and (c) with these methodological developments, specific experiments will be concerned with an evaluation of a frequency theory of verbal discrimination learning. With regard to "a" above, experiments will be designed to demonstrate that variations in number of exposures of events can affect the perceived frequency of their occurrence without affecting recall probability (strength). Individual estimates of event frequency and records of rehearsal responses will provide the basis for assessing individual subjective frequency values of events. Initial experiments will be designed to evaluate intuitive and theoretical predictions relating "frequency value" and verbal discrimination performance.